<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <script src="js/vue.js"></script>
</head>
<body>
    <div id="app">
        <h3 id="h3">{{message}}</h3>
    </div>
    <script>
        var vm = new Vue({
            el: '#app',
            data: {
                message: 'hello world!'
            },
            methods: {
                show(){
                    console.log('执行了 show 方法')
                }
            },
            beforeMount(){
                console.log(document.getElementById('h3').innerText)    
            }
        })
    </script>
</body>
</html>